I did rewatch the episode, and my interpretation is completely the opposite.
Lon Shapiro

We will have to agree to disagree a bit on this one,

My reason for wondering was that a decent number of Unsullied were visible and very dead strewn all around the somewhat sizable skeleton crew of dead Lannister guards (as Grey Worm and his buddy check out the burning ships).

No biggie either way, glad Grey Worm and his platoon survive to inject Westeros with silent and obedient diversity (see Benioff and Weiss new HBO project about the Confederacy, great timing guys).

Oh, and apparently, we will have until 2019 to wait for the final season.